Following its stellar critical reception, the truth-based Iranian-hostage crisis thriller directed by and starring Ben Affleck earned an estimated $20.1 million — surpassing expectations — and landed in number two for its opening weekend at the box office, according to early estimates.

Liam Neeson's Taken 2, in its second weekend in theaters, held onto the top spot with an additional $22.2 million. The news wasn't as good for Kevin James, whose new comedy Here Comes the Boom went, well, bust, earning just $12 million and landing in fifth place, which is the worst opening in James' big-screen career.

Argo, which is now a lead contender for awards season 2012-2013, is the biggest opening for a film starring Affleck since 2003's disastrous Daredevil.

Just in time for the Halloween season, Ethan Hawke's horror film Sinister — which cost just $3 million to make — scored at third place with $18.3 million. Seven Psychopaths, starring Colin Farrell, made just $4.3 million its first weekend out, landed it at number 9.